External center grinder



EXTERNAL CENTER GRINDER Filed April 17, 1929 2 Sheets-Sheet l V F 2 vINVENTOR. Mmf- 2g g/ 2M TPdzzZe A TTORNE Y.

Aug. 25, 1931. c. T. RAULE EXTERNAL CENTER GRINDER Filed April 17, 19292 Sheetg-Sheet 2 ATTORNEY INVENTOR Patented Aug. 25, 1931 PATENT OFFICECLIFFORD '1. RAULE, OF BROOKLINE, PENNSYLVANIA EXTERNAL CENTER GRINDERApplication filed April 17,

My invention relates to grinding machine for tity of like articles.

A purpose of'my invention is to use an a multiple external grinding alarge quaneccentricity between the grinding disc face of a grin g wheeland the common orbit of planetary work-holders adapted to presentduplicate work pieces thereto for traversing the work wheel surface.

A further purpose is to support workholders atspaced intervals around aturntable upon upwardly extending parallel links pivoted at oppositeends respectively to the work-holders and to the table and to use anradially inwardly to straighten up the supexternal cam common to all ofthe work-holders for feeding the work-holders upwardly against thedownwardly directed face of a grinding wheel by moving the work-holdersporting links of the holders.

A further purpose is to provide efiicient mechanism for automaticallyunloading and loading the planetary work-holders of an ex ternalgrinding machine.

Further purposes will appear in the specification and in the claims. V

I have elected to show one only of the forms of my invention, selectinga form that is prac- 80 tical and efficient in operation and thatillustrates volved.

Figure 1 is a broken top plan View showing structure embodying myinvention.

Figure 2 is a vertical section taken upon the line 2-2 of Figure 1.

Figure 3 is a fragmentary plan view of one of the work-holders.

Figures 4 and 5 are end and side elevations, respectively, partlysectioned, of Figure 3.

Like numerals refer to like parts in all figures.

Referrin to the drawings,

particularly well the principles inand describing in illustration andnot in l1mitation:

The present invention utilizes an eccentric relation between thedownwardly rdirected disc face 10 of a large grinding wheel 11 and thecommon orbit of work-holders 12 mounted at spaced intervals around aturn-table 13 in order to produce relative traverse of pieces withrespect to the.

1929. Serial No. 355,740.

the engaging surfaces of the work pieces and the wheel.

It also utilizes novel means forfeeding the work-holders toward thewheel face during grinding and novel means for loading and unloading thework-holders.

The stationary supporting structure 14 includes a base 15 and brackets16 and 17 extending upwardly from opposite sides of the base andcarrying respectively the wheel unit and a feed hopper 18.

.The grinding disc wheel is mounted in an annular casing 19 that isrigidly fastened at the lower end of a shaft 20. The shaft is journaledand supported at the inner end of abracket 21 which is supported uponthe guideway bracket 16 of the supporting structure. The wheel unit issupported vertically by .a suitable pressure bearing 22 and isbelt-driven at 23 from a motor 24 mounted upon the bracket 16.

The bracket 21 carrying the Wheel unit is vertically adjustable in itssupporting guideway, downwardly directed screws 25 from the bottom ofthe bracket 21 representing heads against an upwardly directed surface26 of 76 the supporting structure.

7 The turntable is of larger diameter than the grinding wheel andisjournaled upon a central stationary post 27 extending up from thesupporting structure. The grinding wheel and turn-table are relativeeccentric and of different diameters, opposing one another .at one sideand being relatively offset at the other, so that the radial position ofeach work-holder onthe, turn-table is variant with respect to the faceof the grinding wheel according to its orbital position around thewheel.;

The work-holders 12 are mounted at spaced intervals around theturn-table and 80 are adapted to present work pieces againstthe grindingface of the wheel while traveling along a portion of their orbit at oneside of the machine.

Each work-holder comprises a center chuck 28 supported upon fourupwardly extending parallel links 29 that are pivotally connected attheir upper ends to the chuck and at their lower ends to upwardlyextending lugs 30 from the turntable.

The center chuck includes an outer dead center spindle 31 in a tailportion of the chuck and a co-axial live center spindle 32 in a head atthe inner end of the chuck.

The dead center spindle is spring-pressed inwardly at 33 and carries aflange 31 at its outer end for use in pulling back the spindle foropening the chuck.

The live center spindle carries an offset drive pin 35 and is driventhrough meshing gear wheels 36 and 37 that are preferably respectivelyco-axial with the upper and lower pivots of the inner pair of supportinglinks 29 so that angular deflection of the links may not interfere withthe gear drive of the live spindle.

The chucks are spring-pulled outwardly at 38, outward movement beinglimited by engagement between a feed cam 39 with the ends of arms -10projecting from the tail ends of the chucks.

The effective lengths of the arms 40 are adjustable by screwing into thechuck members.

The feed cam 39 which surrounds the turn-table simultaneously controlsthe inward positions of all of the chucks and along the grinding portionof the orbit progressively feeds the carriers inward so as to straightenup the links, and thereby feed the chucks and the work pieces held inthe chucks upwardly.

The carriers and work-holders are duplicate and operate alike.

The individual live center spindles are driven in any suitable way andoperate to rotate the work pieces by means of the offset pins 35 whichenter suitable recesses 41 in the work pieces in order to rotate thework piece.

The turn-table is driven by a motor 42 mounted on the supportingstructure, the shaft of the motor carrying a pinion 13 n1esh ing withexternal gear teeth 44 upon the outside of the table.

The live center spindles of the chuck members are rotated fromindividual downwardly extending shafts 45 which journal in suitablebearings 46 through the turntable, are geared at 47 to rotate the trainsoperating the live spindles and extend downwardly through the turn-tablewhere they carry small gear wheels 48 meshing with stationary gear teeth49 around a central portion 50 of the supporting structure.

The gear 47 upon the upper end of each shaft 45 is the first of a trainof gears connected to drive the live center spindle of the work-holder.

The work pieces 51 are fed one after another into the successivework-holders from the mouth 52 of a rectangular tower reservoir 53.

The delivery from the supply tower is controlled by the oscillation of arocker lever 54 carrying upper and lower links 55 and 56 that move inopposite directions in and out across the tower above and below thelowermost position of pieces. The rocker is spring-pulled at 57 tomaintain it in position in which the lower link 06 is inward below thebottom work piece, blocking the piece from moving downward.

As the empty chuck members move he neath the mouth of the supply tower,the head of the chuck engages a forwardly tiaring arm 58 from the rockerdeflecting the rocker against the action of the spring 57 in a way tocause the upper link 55 to move in to block the descent of the workpieces above the lowermost piece and the lower arm 56 moving out andreleasing the bottom piece, letting it fall from the mouth of the towerinto chuck between the live and dead centers, which at this time arespread apart to receive the new work piece.

The rocker member springs back to its initial position as soon as theturn-table carries the chuck beyond the arm 58, the upper link 55pulling out from below the pile of work pieces, permitting their descentto the lower link 56, which has moved into blocking position before theupper link has effected its release of the upper pieces.

The dead spindle of each work holder is drawn back to release thefinished work piece by an engagement between the inner face of theflange 34 and the outer face of a release cam 59.

\Vhcn thus released the work piece momentarily lies loosely upon the bedof the chuckto be pushed off an instant later by engaging a stationarydownwardly extending arm 60 from the supporting structure, and fallingthrough asuitable opening (51 in the turn-table enters a discharge chute62 which delivers it into any suitable receptacle.

In operation the operator maintains the supply tower 53 charged withwork pieces to be externally ground. These duplicate work pieces.already centered and grooved for the chucks, are delivered one afteranother by the rocker feed member 54 to the successive chucks as theypass beneath the mouth of the tower, the dead center spindle of eachchuck being drawn back at the time the work piece is delivered into thechuck.

Following the course of a single workholder around its orbit,a-lmostimmediately after the holder receives a. work piece from the mouth ofthe feed tower it reaches a position at which the cam 59 releases theflange 34 of the dead center spindle, and the spindle springs inwardlyautomatically centering the work piece, the off-set pin of the livecenter spindle quickly finding its groove 41 of the work piece to rotatethe piece.

The supporting links 29 of the chuck are at this time inclined outwardlywith a resnlt that the upper surface of the work piece is somewhat belowthe grinding face of the wheel.

As the turn-table revolves the work piece is brought into a position 63at which its full length is beneath the grinding surface of the discwheel, and the height of the wheel and the length of the feed arm 40have preferably been so adjusted that grinding begins at about thistime. i

The work piece moves gradually transversely inwardly across the discwhile travelder the wheel, so that the upward feed of the work piece hasceased before the piece has begun to leave the wheel.

From the position 65 the work piece moves gradually outwardly frombeneath the wheel and downwardly until at a point 66 upon the other sideof the machine the chuck is opened by an engagement between the releasecam 59 and the flange 34 on the outer end of the dead center spindle,the spindle being drawn back and releasing the work piece.

After release the Work piece is pushed off the chuck by the arm 60 thenthe empty open chuck again reaches the supply tower, completing thecycle. At the supply tower it receives a new work piece beginning a newcycle.

In view of my invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in' the art, to obtain all or part of the benefits of myinvention without copying the structure shown, and I, therefore, claimall such 111: so far as they fall within the reasonable spirit and scopeof my invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is 1. In a multiple external grinding machine,a disc wheel, a turn-table parallel and eccentric thereto, work-holdersspaced at uniform intervals around the turn-table, parallel linkssupporting individual holders from the table pivoted at one end to thetable and at the other to the work-holder, and a feed cam surroundingthe turn-table adapted to feed the holders radially of the turn-table inorder to feed the work-holders in a direction axial of the turn-tabletoward the face of the wheel by changing the angular position of thelinks.

2, In a multiple external grinding machine, a disc wheel, a turn-tableparallel and eccentric thereto, chucks at spaced intervals around theturn-table having link support from the turntable and positioned withrespect to the face of the wheel by the angular position of the linkswith respect to the tnrntable, means resiliently pressing the chucksoutwardly, a feed cam surrounding the turn table and limiting theoutward positionof the chucks and thereby their position with respect tothe face of the wheel, and means for rotating the chucks during therotation of the turn-table. V v

' 3. In a multiple external grinding machine, a downwardly directed discgrinding wheel, an upwardly directed turntable parallel and eccentricthereto, work-holders spaced at uniform intervals around the turntable,and parallel links supporting the individual holders from the tablepivoted at one end to the table and at the other to the work-holder, incombination with gearing adapted to rotate the holder having cooperatingwheels coaxial with the pivots of ne of the links.

4. In a multiple external grinding machine, a disc wheel and aturn-table parallel and eccentric thereto, in combination withwork-holders spaced around the turn-table, each comprising radiallyspaced heads, dead and live center spindles therein, resilient meanspressing the dead center spindle inwardly, means for driving the livecenter spindle adapted to connect the spindle with the work piece duringrotation so as to drive the work piece simultaneously with the spindle,parallel upwardly extending supporting links pivoted at the upper end tothe workholder and at the lower end to the table, and cam means fordrawing back the dead center spindle to release the Work pieces from theholder.

5. In a multiple external grinding machine, a downwardly directed discgrinding wheel, an upwardly directed turn-table parallel and eccentricthereto, work-holders spaced around the turn-table, each includingspaced heads and a dead center spindle longitudinally slidable andspring-pressed inwardly in one of the heads and each adapted to presenta work piece to the disc surface of 6. In a multiple external grindingmachine. a downwardly directed disc grinding wheel, an upwardly directedturn-table parallel and eccentric thereto, Work-holders spaced aroundthe turn-table, each including spaced heads and a dead center spindlelongitudinally slidable and spring-pressed inwardly in one. of the headsand each adapted to present a work piece to the disc surface of thewheel throughout a portion of the orbit of the holder, in combinationwith cam means mounted upon supporting structure adjacenta portion ofthe orbit of the holder away from the disc wheel, and adapted towithdrawthe spindle to loosen the work piece from the holder, an inwardlyextending member adjacent the cam adapted to engage the loosened workpiece to remove it from the holder, adjacent and after the projectingmember, and a one-at-a-time feed member at the mouth thereof having anoperating arm engaged by the empty work-holder when the holder is inposition to receive a new work piece from the tower.

CLIFFORD T. RAULE.

